In the fields of manufacture of articles such as automobiles, household appliances and industrial machines, a metal and a resin often need to be firmly bonded together. Currently, in a conventional method, an adhesive is used at normal temperature or under heating to integrally bond a metal and a synthetic resin. Alternatively, an engineering resin with high strength may also be bonded to a magnesium alloy, an aluminum alloy, or ferroalloys such as stainless steel directly without an adhesive.
Nano molding technology (NMT) is a technique of integrally bonding a metal and a resin, which allows the resin to be directly injection molded on a surface of a metal sheet by nano molding the surface of the metal sheet so as to obtain a metal-resin integrally molded product. For effective bonding of a metal and a resin, NMT may replace commonly used insert molding or zinc-aluminum or magnesium-aluminum die casting so as to provide a metal-resin integrally molded product with low cost and high performance. Compared with the bonding technology, NMT may reduce the weight of the product, ensure excellent strength of the mechanical structure, high processing rate, and high output, allow more appearance decoration methods, applicable to vehicles, IT equipment, and 3C products.
Japan's Taisei Plas Co., Ltd. filed a series of patent applications including, for example, CN1492804A, CN1717323A, CN101341023A and CN101631671A, which disclose methods for integrally molding a metal and a resin composition. For example, by using a resin composition containing polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), and polyamide (PA) with high crystallinity as an injection molding material, the resin composition is directly injection molded on a surface of a nano molded aluminum alloy layer to allow the resin composition to immerse in a nanoscale micropore, so as to obtain a metal-resin integrally molded product with a certain mechanical strength. However, because the resins used in these methods are all highly crystalline resins, the resins cannot be made into components with transparency, thereby restricting the design and application of the product.